Vibhaṅgasutta

Suttapiṭaka · Saṁyuttanikāya · Mahāvaggasaṁyutta · Vol. 19 · Section 1203

[1203] Bhikkhus, when the four bases of spiritual power (iddhipāda) have been developed in this way and cultivated in this way, a bhikkhu wields the various kinds of spiritual power (iddhividha): having been one, he becomes many; having been many, he becomes one … he exercises mastery with his body even as far as the brahmā world.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.

This passage also appears in 1 other place

Vol. 19 · Section 1148 — Mahapphalasutta